• The Journal of Korean Association of Computer Education
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• v.14 no.3
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• pp.13-23
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• 2011

Information Culture Index (ICI) is the quantitative value that represents people's information literacy levels. Also, it diagnoses the people's knowledge, ethics, emotion, and practice synthetically. As the Internet and cell phone addiction have been increasing when people access information on the web recently, it is necessary to analyze the meaning of the ICI from the Internet and cell phone addiction perspectives and to confirm if it goes well in the right direction. In this paper, we analyze the characteristics of the people who have high ICIs. At the same time, we perform the statistical analysis combining ICIs with the Internet and the cell-phone addiction levels. In particular, the meaning of the Information Practicing factor, which is one of the ICI factors, is examined. By doing these, we confirm if the current ICI works correctly or not, and propose a better way for measuring ICIs. In order to do these, we survey and analyze data with basic statistical methods and structural equation model.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.131-136
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• 1994

In the present study, in order to make an in vitro model of gastric mucosa for physiological and pharmacological studies, we established two immortalized gastric surface mucous cell lines (GSM06 and GSM10), which produce periodic acid-Schiff (PAS)-and concanavalin A (Con A)-positive glycoproteins, from a primary culture of gastric fundic mucosal cells of adult transgenic mice harboring a temperature-sensitive simian virus 40 large T-antigen gene 〔1]. Gastric fundic mucosal cells were isolated as a modification of a previously described method for rats by Schepp et al. (2). The isolated gastric fundic mucosal cells were cultured in DME/F12 medium supplemented with 2% fetal bovine serum (FBS), 1% ITES (consisting of 2 mg/1 insulin, 2 mgg/1 transferrin, 0.122 mg/1 ethanolamine and 0.00914 mg/1 sodium selenite) and 10 ng/ml recombinant epidermal growth factor (EGF) in a collagen-coated culture dish. To remove fibroblastic cells from the culture, gastric mucosal cells were incubated in the culture medium containing dispase (25 U/ml) for 24 h. The cells, uncontaminated with fibroblastic cells, were then cloned by colony formation. In our series of three attempts, two cell lines (GSM06 and GSM10) have been established at last. The cells proliferated, attached to the dish ana grew until confluent monolayers were formed, and maintained tight contact with neighboring cells. Both GSM06 and GSM10 cells have now been in culture for more than 9 months with regular passaging. The either cell produced

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.85-96
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• 2003

Normal human skin, constantly challenged by environmental micro-organisms, has an innate ability to fight invading microbes through antimicrobial peptides. These peptides, described in both plant and animal kingdoms are able to inactivate a broad spectrum of micro-organisms. Mammalian defensins constitute one of the most common antimicrobial peptide family. Among the three human beta-defensins hBD1, hBD2 and hBD3 produced in epithelia, only hBD2 and hBD3 are inducible and additionally have been described as expressed by differentiated keratinocytes at site of inflammation and infection. The aims of these studies were to define a cell culture model in which the basal production of hBD could be detected and up-regulated in order to enhance skin auto-protection against micro-organisms. A specific Polymerase Chain Reaction method have been developed for hBD2 and hBD3 mRNA detection in non-differentiated monolayer keratinocytes cell culture. We have been able to demonstrate that in vitro, hBD2 and hBD3 expression in normal human keratinocytes could be detected and enhanced by TNF-alpha and IFN-gamma, in hypercalcic culture conditions. This research opened the possibility of the development of cosmetic active compounds, able to induce the expression of skin natural antibiotic peptides responsible about microflora ecology of the skin.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.277.2-277.2
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• 2013

Petri dishes and glass slides have been widely used as general substrates for in vitro mammalian cell cultures due to their culture viability, optical transparency, experimental convenience, and relatively low cost. Despite the aforementioned benefit, however, the flat two-dimensional substrates exhibit limited capability in terms of realistically mimicking cellular polarization, intercellular interaction, and differentiation in the non-physiological culture environment. Here, we report a protocol of culturing embryonic rat hippocampal neurons on the electro-spun polymeric network and the results from examination of neuronal cell behavior and network formation on this culture platform. A combinatorial method of laser-scanning confocal fluorescence microscopy and live-cell imaging technique was employed to track axonal outgrowth and synaptic connectivity of the neuronal cells deposited on this model culture environment. The present microfiber-based scaffold supports the prolonged viability of three-dimensionally-formed neuronal networks and their microscopic geometric parameters (i.e., microfiber diameter) strongly influence the axonal outgrowth and synaptic connection pattern. These results implies that electro-spun fiber scaffolds with fine control over surface chemistry and nano/microscopic geometry may be used as an economic and general platform for three-dimensional mammalian culture systems, particularly, neuronal lineage and other network forming cell lines.

• The Korean Journal of Pain
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• v.35 no.2
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• pp.160-172
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• 2022

Background: The authors established an in vitro model of diabetic neuropathy based on the culture system of primary neurons and Schwann cells (SCs) to mimic similar symptoms observed in in vivo models of this complication, such as impaired neurite extension and impaired myelination. The model was then utilized to investigate the effects of insulin on enhancing neurite extension and myelination of diabetic neurons. Methods: SCs and primary neurons were cultured under conditions mimicking hyperglycemia prepared by adding glucose to the basal culture medium. In a single culture, the proliferation and maturation of SCs and the neurite extension of neurons were evaluated. In a co-culture, the percentage of myelination of diabetic neurons was investigated. Insulin at different concentrations was supplemented to culture media to examine its effects on neurite extension and myelination. Results: The cells showed similar symptoms observed in in vivo models of this complication. In a single culture, hyperglycemia attenuated the proliferation and maturation of SCs, induced apoptosis, and impaired neurite extension of both sensory and motor neurons. In a co-culture of SCs and neurons, the percentage of myelinated neurites in the hyperglycemia-treated group was significantly lower than that in the control group. This impaired neurite extension and myelination was reversed by the introduction of insulin to the hyperglycemic culture media. Conclusions: Insulin may be a potential candidate for improving diabetic neuropathy. Insulin can function as a neurotrophic factor to support both neurons and SCs. Further research is needed to discover the potential of insulin in improving diabetic neuropathy.

• Biomolecules & Therapeutics
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• v.24 no.3
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• pp.260-267
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• 2016

Mesenchymal stem cells (MSCs) offer significant therapeutic promise for various regenerative therapies. However, MSC-based therapy for injury exhibits low efficacy due to the pathological environment in target tissues and the differences between in vitro and in vivo conditions. To address this issue, we developed adipose-derived MSC spheroids as a novel delivery method to preserve the stem cell microenvironment. MSC spheroids were generated by suspension culture for 3 days, and their sizes increased in a time-dependent manner. After re-attachment of MSC spheroids to the plastic dish, their adhesion capacity and morphology were not altered. MSC spheroids showed enhanced production of hypoxia-induced angiogenic cytokines such as vascular endothelial growth factor (VEGF), stromal cell derived factor (SDF), and hepatocyte growth factor (HGF). In addition, spheroid culture promoted the preservation of extracellular matrix (ECM) components, such as laminin and fibronectin, in a culture time- and spheroid size-dependent manner. Furthermore, phosphorylation of AKT, a cell survival signal, was significantly higher and the expression of pro-apoptotic molecules, poly (ADP ribose) polymerase-1 (PARP-1) and cleaved caspase-3, was markedly lower in the spheroids than in MSCs in monolayers. In the murine hindlimb ischemia model, transplanted MSC spheroids showed better proliferation than MSCs in monolayer. These findings suggest that MSC spheroids promote MSC bioactivities via secretion of angiogenic cytokines, preservation of ECM components, and regulation of apoptotic signals. Therefore, MSC spheroid-based cell therapy may serve as a simple and effective strategy for regenerative medicine.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.3
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• pp.761-766
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• 2012

Objective: Although various human cancer stem cells (CSCs) have been defined, their applications are restricted to immunocompromised models. Developing a novel CSC model which could be used in immunocompetent or transgenic mice is essential for further understanding of the biomolecular characteristics of tumor stem cells. Therefore, in this study, we analyzed murine lung cancer cells for the presence of CSCs. Methods: Side population (SP) cells were isolated by fluorescence activated cell sorting, followed by serum-free medium (SFM) culture, using Lewis lung carcinoma cell (LLC) line. The self-renewal, differentiated progeny, chemosensitivity, and tumorigenic properties in SP and non-SP cells were investigated through in vitro culture and in vivo serial transplantation. Differential expression profiles of stem cell markers were examined by RT-PCR. Results: The SP cell fraction comprised 1.1% of the total LLC population. SP cells were available to grow in SFM, and had significantly enhanced capacity for cell proliferation and colony formation. They were also more resistant to cisplatin in comparison to non-SP cells, and displayed increased tumorigenic ability. Moreover, SP cells showed higher mRNA expression of Oct-4, ABCG2, and CD44. Conclusion: We identified SP cells from a murine lung carcinoma, which possess well-known characteristics of CSCs. Our study established a useful model that should allow investigation of the biological features and pharmacosensitivity of lung CSCs, both in vitro and in syngeneic immunocompetent or transgenic/knockout mice.

• Preventive Nutrition and Food Science
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• v.16 no.3
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• pp.217-223
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• 2011

Ischemic stroke constitutes about 80% of all stroke incidences. It is characterized by brain cell death in a region where cerebral arteries supplying blood are occluded. Under these ischemic conditions, apoptosis is responsible for the cell death, at least in part. Goat's-beard (Aruncus dioicus var. kamtschaticus) is a perennial plant that grows naturally in the alpine regions of Korea. In the present study, we first determined whether water extract of goat's-beard (HY1646) and some of its fractions prepared by partitioning with organic solvents could improve the viability of human hepatocellular carcinoma cells (HepG2) cultured under hypoxic condition by blocking apoptotic pathways. Based on the in vitro findings, we subsequently investigated whether HY1646 and the ethyl acetate fraction (EA) selected from cell culture-based screening could attenuate brain injury in a rat middle cerebral artery occlusion (MCAO) model of ischemia (2 hr), followed by 22 hours of reperfusion. The cell number was sustained close to that initially plated in the presence of HY1646 even after 24 hr of cell culture under hypoxic condition (3% $O_2$), at which time the cell number reached almost zero in the absence of HY1646. This improvement in cell viability was attributed to the delay in apoptosis, identified by the formation of DNA ladder in gel electrophoresis. Of fractions soluble in hexane, ethyl acetate (EA) and butanol, EA was chosen for the animal experiments because EA demonstrated the best cell viability at the lowest concentration (10 ${\mu}g$/mL). HY1646 (200 mg/kg) and EA (10 and 20 mg/kg) significantly reduced infarct size, an index of brain injury, by 16.6, 40.0 and 61.0%, respectively, as assessed by 2,3,5-triphenyl tetrazolium chloride staining. The findings suggest that prophylactic intake of goat's beard might be beneficial for preventing ischemic stroke.

• Biomolecules & Therapeutics
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• v.13 no.4
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• pp.199-206
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• 2005

Cell therapy (CT) is a group of techniques to treat human disorders by transplantation of cells which have been processed and propagated independent of the living body. Blood transfusion and bone marrow transplant have been the primary examples of cell therapy. With introduction of stem cell (SC) technologies, however, CT is perceived as the next generation of biologies to treat human diseases such as cancer, neurological diseases, and heart disease. Despite potential of cell therapy, insufficient guidelines have been implemented concerning safety test and regulation of cell therapy. This review addresses the safety issues to be resolved for the cell therapy, especially SC therapy, to be successfully utilized for clinical practice. Adequate donor cell screening must preceed to ensure safety in cell therapy. In terms of SC culture, controlled, standardized practices and procedures should be established. Further molecular studies should be done on SC development and differentiation to enhance safety level in cell therapy. Finally, animal model must be further installed to evaluate toxicity, new concepts, and proliferative potential of SC including alternative feeder layer of animal cells.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.241-246
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• 1989

Continuous on-line monitoring of cell concentration and growth rate in aerobic batch fermentation process was carried out by analyzing the exhaust gas composition of tormentor with a quadrupole mass spectrometer. From the mass spectrometric analyses of major gaseous components, i.e. $N_2$, $O_2$, $CO_2$ and $H_2O$, and the material balance equations for oxygen and carbon dioxide, oxygen uptake rate (OUR) rind carbon dioxide evolution rate (CER) were instantaneously calculated using a computer (16-bit IBM PC-AT) interfaced to a quadrupole mass spectrometer. The calculated OUR and CER data were used for the estimation of cell concentration and growth rate of Candida utilis during batch culture. It was found that the cell concentration could be satisfactorily estimated from the data of OUR arid CER during the culture and this method could be successfully und for the continuous monitoring of cell growth and growth rate.